Factorial Prime

A Prime of the form $n!\pm 1$. $n!+1$ is Prime for 1, 2, 3, 11, 27, 37, 41, 73, 77, 116, 154, 320, 340, 399, 427, 872, 1477, ... (Sloane's A002981) up to a search limit 4850. $n!-1$ is Prime for 3, 4, 6, 7, 12, 14, 30, 32, 33, 38, 94, 116, 324, 379, 469, 546, 974, 1963, 3507, 3610, ... (Sloane's A002982) up to a search limit of 4850.

References

Borning, A. ``Some Results for $k!+1$ and $2\cdot 3\cdot 5\cdot p+1$.'' Math. Comput. 26, 567-570, 1972.

Buhler, J. P.; Crandall, R. E.; and Penk, M. A. ``Primes of the Form $M!+1$ and $2\cdot 3\cdot 5\cdots p+1$.'' Math. Comput. 38, 639-643, 1982.

Caldwell, C. K. ``On the Primality of $N!\pm 1$ and $2\cdot 3\cdot 5\cdots p\pm 1$.'' Math. Comput. 64, 889-890, 1995.

Dubner, H. ``Factorial and Primorial Primes.'' J. Rec. Math. 19, 197-203, 1987.

Guy, R. K. Unsolved Problems in Number Theory, 2nd ed. New York: Springer-Verlag, p. 7, 1994.

Sloane, N. J. A. Sequences A002981/M0908 and A002982/M2321 in ``An On-Line Version of the Encyclopedia of Integer Sequences.'' http://www.research.att.com/~njas/sequences/eisonline.html and Sloane, N. J. A. and Plouffe, S. The Encyclopedia of Integer Sequences. San Diego: Academic Press, 1995.

Temper, M. ``On the Primality of $k!+1$ and $\cdot 3\cdot 5\cdots p+1$.'' Math. Comput. 34, 303-304, 1980.